This invention relates to expandable arrays of electromagnetic radiating elements and sonar transducers, and more particularly to an expandable array wherein structural rigidity is obtained by urging the radiating elements or transducers against a flexible enclosure.
Arrays of electromagnetic radiating elements and arrays of sonar transducers are sometimes provided with the facility of being stowed in a configuration which is much smaller than the overall dimensions of the array when the radiating elements of transducers are being deployed for the transmission and reception of radiant energy. A situation frequently encountered by sonar transducers is that in which an array of transducers is dropped from an aircraft into the ocean, the array of transducers being stowed in a compact configuration during the airdrop so as to protect the transducers at the time of impact with the surface of the ocean, the transducers then being allowed to move apart from each other under water to provide an array of the transducers having a desired configuration.
A problem arises in that the stowage of transducer elements in a protective housing is best accomplished with a minimum of additional weight and equipment utilized in positioning the trnasducer elements in their respective positions in the underwater array. An additional problem arises in that in certain applications, the array of transducers is required to have a rigid configuration independently of water movement to insure a prescribed pattern of radiation.